formal language

A formal language consists of words whose letters are taken from an alphabet and are well-formed according to a specific set of rules called a formal grammar.

An alphabet can be any set; its elements are called letters.

A word over an alphabet can be any finite sequence of letters. The length of a word is the number of letters it is composed of.

Words that belong to a particular formal language are sometimes called well-formed words.

Formally,
a formal language $L$ over an alphabet $\mathrm{\Sigma }$ is a subset of ${\mathrm{\Sigma }}^{\ast }$ (where ${\mathrm{\Sigma }}^{\ast }$ is the set of all words over the alphabet $\mathrm{\Sigma }$).

Sometimes, sets of words are grouped into expressions, and rules/constraints may be chosen for the creation of "well-formed expressions".

#WIP

Grammar